WO2011040263A1

WO2011040263A1 - Injection needle assembly and drug injection device

Info

Publication number: WO2011040263A1
Application number: PCT/JP2010/066133
Authority: WO
Inventors: 横田　崇之; 陽一郎岩瀬; 資文菱川; 吏高橋
Original assignee: テルモ株式会社
Priority date: 2009-09-30
Filing date: 2010-09-17
Publication date: 2011-04-07
Also published as: KR101690356B1; AU2010301852B2; RU2012110406A; CA2770829A1; TWI449552B; SG177466A1; JPWO2011040263A1; EP2484398A4; ZA201109203B; CN102470215B; EP2484398B1; US20110077602A1; CN102470215A; KR20120091032A; BR112012004393B1; TW201113060A; JP5667571B2; US8636705B2; BR112012004393A8; AU2010301852A1

Abstract

Provided are an injection needle assembly and drug injection device which reduce the amount of drug residue as a result of a structure which does not require precise adjustment of the position of the base end of a needle tube with respect to a needle hub. An injection needle assembly (2) comprises a needle tube (5) which has a needle tip (5A) for puncturing the skin, a needle hub (6), and an elastic member (7). The needle hub (6) comprises a first member (11) for holding the needle tube (5), and a second member (12) for insertion of an evacuation part (52) of a syringe (3). The elastic member (7) is disposed inside the second member (12) and adheres in a liquid-tight manner to the inside surface of the second member, and the elastic member (7) has a through hole (45) through which the needle tube (5) is allowed to pass.

Description

Injection needle assembly and drug injection device

The present invention relates to an injection needle assembly and a drug injection device that reduce the remaining amount of drug.

A drug injection device such as a syringe may suck a drug from a vial. The vial is a drug storage container that can store the drug in a liquid or lyophilized state for a long period of time. The opening of the vial is usually sealed with a rubber stopper having a thickness of about 3 to 5 mm. Since this rubber stopper prevents the drug from leaking even if the needle tube is punctured a plurality of times, most of the vaccines frequently inoculated by a group are sucked from the vial.

In a general method for sucking a drug from a vial into a syringe, first, a needle hub to which a needle tube for suction of about 22 gauge is attached is connected to the syringe. Next, a needle tube for suction is inserted into the vial and the drug solution is sucked into the syringe. Thereafter, the hub to which the needle tube for suction is attached is removed from the syringe, and the hub to which the needle tube for injection is attached is attached to the syringe. Thereby, the medicine injection device is in a state where the medicine can be injected. After the drug is injected (administered) into the living body by the drug injection device, the drug remains in the needle tube, the hub, and the tip of the syringe.

The skin is composed of three parts: epidermis, dermis, and subcutaneous tissue. The epidermis is a layer of about 50 to 200 μm from the skin surface, and the dermis is a layer of about 1.5 to 3.5 mm continuing from the epidermis. Influenza vaccines are generally administered subcutaneously or intramuscularly, and are therefore administered in the lower layer of the skin or deeper.

On the other hand, it has been studied to reduce the dose of the vaccine by administering the influenza vaccine with the upper skin layer where many immunocompetent cells are present as the target site. The upper skin layer refers to the epidermis and dermis of the skin. The dose of the vaccine to the upper skin layer is about 50 to 300 μL, preferably about 100 μL. Therefore, if the amount of the remaining drug is large, the advantage of reducing the amount of antigen obtained by administering the vaccine to the upper layer of the skin becomes small.

Furthermore, drug administration to the upper layer of the skin requires a higher injection pressure than subcutaneous administration. For this reason, when the remaining amount of air accumulated in the engagement portion between the syringe and the hub increases, the remaining air becomes a pressure interference band, and there is a possibility that an accurate dose cannot be ensured.

As a technique for reducing the remaining amount of drug, for example, there is a technique described in Patent Document 1. An insertion member and a stop member are formed on the needle base of the injection needle described in Patent Document 1. The insertion member is made of a material such as elastic synthetic rubber or synthetic resin. The insertion member connects the injection needle to the injection cylinder and fills the dead volume of the attachment port (tip) of the injection needle formed at the tip of the injection cylinder. It is like that. The stop member is fitted to the tip of the syringe barrel.

Further, as another technique for reducing the remaining amount of the drug, there is a technique described in Patent Document 2. The syringe described in Patent Document 2 is configured such that an injection needle and an outer cylinder having a cylinder tip into which the injection needle is inserted can be separated. The diameter of the cylinder tip of the outer cylinder increases as the opening thereof goes to the tip side. Then, the injection needle inserted into the tube tip is fitted and brought into contact with the smallest diameter portion of the tube tip.

Japanese Utility Model Publication No. 61-28629 JP 2006-116217 A

However, with the injection needle described in Patent Document 1, the work of inserting the insertion member into the tip of the syringe barrel becomes complicated. As described above, when a drug is aspirated from a vial, it is necessary to attach a suction needle and an injection needle to the outer cylinder. For this reason, the injection needle described in Patent Document 1 is unsuitable when used by sucking a drug from a vial.

On the other hand, since the diameter of the syringe described in Patent Document 2 increases as the opening formed at the end of the outer cylinder goes to the distal end side, the injection needle is used when the hub is fitted to the outer cylinder. Can be easily inserted into the tube tip. However, in the syringe described in Patent Document 2, it is necessary to insert the needle tube to a predetermined length into the cylinder tip of the outer cylinder and to fit the smallest diameter part of the cylinder tip. For this reason, the syringe described in Patent Document 2 has a problem that the proximal end (terminal end) of the needle tube must be precisely positioned with respect to the hub portion that is fitted to the outer cylinder.
In addition, when the syringe barrel and the syringe needle are taper-fitted, there is a situation that a dead volume is generated between the tip end portion of the syringe barrel and the needle tube.

The present invention has been made in view of such a situation, and an object of the present invention is to reduce the residual amount of a drug with a structure that does not require precise adjustment of the position of the proximal end of the needle tube with respect to the needle hub.

The injection needle assembly of the present invention includes a needle tube having a needle tip that is punctured into the skin, a needle hub, and an elastic member. The needle hub has a first member that holds the needle tube and a second member into which the discharge portion of the syringe is inserted. The elastic member has an insertion hole that is disposed inside the second member, is in liquid-tight contact with the inner surface of the second member, and allows the needle tube to pass therethrough.

The drug injection device of the present invention includes a syringe having a discharge part, a needle tube having a needle tip punctured on the skin, a needle hub, and an elastic member. The needle hub has a first member that holds the needle tube and a second member into which the discharge portion of the syringe is inserted. The elastic member is disposed inside the second member and is in liquid-tight contact with the inner surface of the second member. This elastic member has an insertion hole through which the needle tube is inserted.

In the injection needle assembly and the drug injection device of the present invention, the needle tube is inserted through the elastic member arranged inside the second member, and the discharge part of the syringe is inserted into the second member. Thereby, the discharge part of the syringe and the needle tube can be communicated without precisely positioning the proximal end of the needle tube with respect to the needle hub. Furthermore, the dead volume in the needle hub can be reduced by reducing or eliminating the distance between the distal end of the discharge portion of the syringe and the elastic member, and the remaining amount of the medicine can be reduced.

According to the injection needle assembly and the drug injection device of the present invention, the remaining amount of drug can be reduced with a structure that does not require precise adjustment of the position of the needle tube with respect to the needle hub.

It is a side view of a 1st embodiment of a medicine injection device of the present invention. It is an exploded view of a 1st embodiment of a medicine injection device of the present invention. It is sectional drawing of 1st Embodiment of the pharmaceutical injection device of this invention. It is sectional drawing which decomposes | disassembles and shows 1st Embodiment of the chemical injection apparatus of this invention. FIG. 5A is a side view of a state where a needle tube is held by the first member according to the first embodiment of the drug injection device of the present invention, and FIG. 5B is a state where the second member is connected to the first member holding the needle tube. It is explanatory drawing which shows. It is sectional drawing of 2nd Embodiment of the chemical injection apparatus of this invention. It is sectional drawing of 3rd Embodiment of the chemical injection apparatus of this invention. It is sectional drawing which decomposes | disassembles and shows 3rd Embodiment of the chemical injection apparatus of this invention. It is sectional drawing of the elastic member which concerns on 4th Embodiment of the chemical injection apparatus of this invention.

Hereinafter, embodiments for carrying out the injection needle assembly and the drug injection device of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the common member in each figure.

1. First embodiment [drug injection device]
First, a first embodiment of a drug injection device and a needle assembly according to the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a side view of a first embodiment of a drug injection device. FIG. 2 is an exploded view of the first embodiment of the drug injection device.

The drug injection device 1 is used when the needle tip is punctured from the skin surface and the drug is injected into the upper layer of the skin. This medicine injection device 1 is composed of an injection needle assembly 2 and a syringe 3 to which the injection needle assembly 2 is detachably connected.

As shown in FIG. 2, the injection needle assembly 2 includes a hollow needle tube 5 having a needle hole, a needle hub 6 to which the needle tube 5 is fixed, an elastic member 7 disposed in the needle hub 6, a needle. A cap 8 is detachably attached to the hub 6. The needle hub 6 includes a first member 11 that holds the needle tube 5 and a second member 12 into which a later-described discharge portion 52 of the syringe 3 is inserted.

Next, the injection needle assembly 2 and the syringe 3 will be described with reference to FIGS. 3 and 4.
FIG. 3 is a cross-sectional view of the drug injection device 1. FIG. 4 is an exploded cross-sectional view of the medicine injection device 1.

[Injection needle assembly]
The needle tube 5 of the injection needle assembly 2 has a size of 26 to 33 gauge (outer diameter 0.2 to 0.45 mm) based on the ISO medical needle tube standard (ISO9626: 1991 / Amd.1: 2001 (E)). Those of 30 to 33 gauge are preferably used.

A needle tip 5A having a blade surface 5a is provided at one end of the needle tube 5. Hereinafter, the other end of the needle tube 5 opposite to the needle tip 5A is referred to as a “base end 5B”. The axial length of the needle tube 5 on the blade surface 5a (hereinafter referred to as “bevel length B”) may be 1.4 mm (adult) or less, which is the thinnest thickness of the upper skin layer described later. The bevel length may be about 0.5 mm or more when a short bevel is formed on a 33 gauge needle tube. That is, the bevel length B is preferably set in the range of 0.5 to 1.4 mm.

Further, the bevel length B is more preferable if the thinnest thickness of the upper skin portion is 0.9 mm (child) or less, that is, the bevel length B is in the range of 0.5 to 0.9 mm. The short bevel refers to a blade surface that is generally used for injection needles and forms an angle of 18 to 25 ° with respect to the longitudinal direction of the needle.

Examples of the material of the needle tube 5 include stainless steel, but are not limited thereto, and aluminum, aluminum alloy, titanium, titanium alloy, and other metals can be used. Further, the needle tube 5 can be not only a straight needle but also a tapered needle at least partially tapered. As the tapered needle, the proximal end portion has a larger diameter than the needle distal end portion, and the intermediate portion may have a tapered structure. Further, the cross-sectional shape of the needle tube 5 may be not only a circle but also a polygon such as a triangle.

Next, the needle hub 6 will be described.
The first member 11 and the second member 12 of the needle hub 6 are formed as separate members. The second member 12 is connected to the first member 11 that holds the needle tube 5. Examples of the material of the first member 11 and the second member 12 include synthetic resins such as polycarbonate, polypropylene, and polyethylene.

The first member 11 includes a base portion 15, an adjustment portion 16, a stabilization portion 17, and a guide portion 18. The base portion 15 is formed in a substantially columnar shape, and has end faces 15a and 15b perpendicular to the axial direction. The adjustment portion 16 is provided at the center of the end surface 15 a of the base portion 15, and includes a columnar convex portion that protrudes in the axial direction of the base portion 15. The axis of the adjustment portion 16 is coincident with the axis of the base portion 15.

A through-hole 21 through which the needle tube 5 passes is provided in the axial center of the base portion 15 and the adjustment portion 16. The base portion 15 is provided with an injection hole 22 (see FIGS. 2 and 4) for injecting the adhesive 20 (see FIG. 3) into the through hole 21. The injection hole 22 is opened on the outer peripheral surface of the base portion 15 and communicates with the through hole 21. That is, the needle tube 5 is fixed to the base portion 15 by the adhesive 20 injected from the injection hole 22 into the through hole 21.

The proximal end 5B side of the needle tube 5 protrudes from the end face 15b of the base portion 15. The base portion 15 is inserted into the second member 12 from the end surface 15b side, and the proximal end 5B side of the needle tube 5 is inserted into an insertion hole 45 described later of the elastic member 7. And the end surface 15b of the base part 15 is contact | abutted to the end surface 41a which the elastic member 7 mentions later.

A connecting piece 24 is provided on the outer peripheral surface of the base portion 15. The connection piece 24 is formed as a ring-shaped flange protruding in the radial direction of the base portion 15, and has

flat surfaces

24 a and 24 b that face the axial direction of the base portion 15. The second member 12 is connected to the flat surface 24 b of the connection piece 24. Further, the distal end portion of the connection piece 24 is a guide portion 18. The guide portion 18 will be described in detail later.

The end surface of the adjusting portion 16 is a needle projecting surface 16a from which the needle tip 5A side of the needle tube 5 projects. The needle projecting surface 16 a is formed as a plane orthogonal to the axial direction of the needle tube 5. This needle protrusion surface 16a defines the depth at which the needle tube 5 is punctured by contacting the surface of the skin when the needle tube 5 is punctured into the upper layer portion of the skin. That is, the depth at which the needle tube 5 is punctured into the upper skin layer is determined by the length of the needle tube 5 protruding from the needle protruding surface 16a (hereinafter referred to as “projection length L”).

The thickness of the upper skin portion corresponds to the depth from the skin surface to the dermis layer, and is generally in the range of 0.5 to 3.0 mm. Therefore, the protruding length L of the needle tube 5 can be set in the range of 0.5 to 3.0 mm.

By the way, the vaccine is generally administered to the upper arm, but in the case of administration to the upper skin part, the shoulder peripheral part where the skin is thick, particularly the deltoid part is preferable. Therefore, the thickness of the upper layer of the deltoid muscle was measured for 19 children and 31 adults. This measurement was performed by imaging the upper layer of the skin with high ultrasonic reflectivity using an ultrasonic measurement device (NP60R-UBM, high-resolution echo for small animals, Nepagene). In addition, since the measured value was logarithmic normal distribution, the range of MEAN ± 2SD was obtained by geometric mean.

As a result, the thickness of the upper skin layer of the deltoid muscle of the child was 0.9 to 1.6 mm. In addition, the thickness of the upper skin layer of the deltoid muscle of adults was 1.4 to 2.6 mm at the distal part, 1.4 to 2.5 mm at the central part, and 1.5 to 2.5 mm at the proximal part. It was. From the above, it was confirmed that the thickness of the upper skin layer in the deltoid muscle was 0.9 mm or more in the case of children and 1.4 mm or more in the case of adults. Therefore, in the injection in the upper layer part of the deltoid muscle, the protruding length L of the needle tube 5 is preferably set in the range of 0.9 to 1.4 mm.

By setting the protruding length L in this way, the blade surface 5a of the needle tip 5A can be reliably positioned on the upper skin layer. As a result, the needle hole (chemical solution discharge port) that opens in the blade surface 5a can be located in the upper skin layer portion at any position in the blade surface 5a. Even if the drug solution outlet is located in the upper skin layer, if the needle tip 5A is stabbed deeper than the upper skin layer, the drug solution flows subcutaneously between the side surface of the end of the needle tip 5A and the cut skin. Therefore, it is important that the blade surface 5a is surely in the upper skin portion.

Note that it is difficult to make the bevel length B 1.0 mm or less with a needle tube thicker than 26 gauge. Therefore, in order to set the protruding length L of the needle tube 5 within a preferable range (0.9 to 1.4 mm), it is preferable to use a needle tube thinner than 26 gauge.

The needle projecting surface 16a is formed so that the distance S from the peripheral edge to the outer peripheral surface of the needle tube 5 is 1.4 mm or less, preferably in the range of 0.3 to 1.4 mm. The distance S from the peripheral edge of the needle protruding surface 16a to the peripheral surface of the needle tube 5 is set in consideration of the pressure applied to the blisters formed by administering the drug to the upper skin layer. That is, the needle projecting surface 16a is set to a size that is sufficiently smaller than the blisters formed on the upper layer portion of the skin and does not prevent the formation of blisters. As a result, even if the needle protruding surface 16a presses the skin around the needle tube 5, it is possible to prevent the administered medicine from leaking.

The stabilizing portion 17 is formed in a cylindrical shape protruding from the flat surface 24 a of the connecting piece 24 provided on the base portion 15. The needle tube 5 and the adjustment unit 16 are disposed in the cylindrical hole of the stabilization unit 17. That is, the stabilizing portion 17 is formed in a cylindrical shape that covers the periphery of the adjusting portion 16 through which the needle tube 5 passes, and is provided away from the needle tip 5A of the needle tube 5 in the radial direction.

The cap 8 is detachably fitted to the stabilizing portion 17. The cap 8 covers the needle tip 5 A of the needle tube 5. Thereby, when attaching needle hub 6 to syringe 3, needle tip 5A can be prevented from touching a user's fingertip. In addition, the used medicine injection device 1 or the needle assembly 2 can be always kept in a safe state, and the user can safely dispose of the used medicine injection device 1 or the needle assembly 2. It can be carried out.

3, the end surface 17a of the stabilizing portion 17 is located closer to the proximal end 5B of the needle tube 5 than the needle protruding surface 16a of the adjusting portion 16. When the living body is punctured with the needle tip 5A of the needle tube 5, the needle projecting surface 16a first contacts the surface of the skin, and then contacts the end surface 17a of the stabilizing portion 17. At this time, the drug injection device 1 is stabilized by the end surface 17a of the stabilizing portion 17 coming into contact with the skin, and the needle tube 5 can be maintained in a posture substantially perpendicular to the skin.

Even if the end surface 17a of the stabilizing portion 17 is positioned on the same plane as the needle projecting surface 16a, or is positioned closer to the needle tip 5A side of the needle tube 5 than the needle projecting surface 16a, the needle tube 5 is skinned. It is possible to keep the posture substantially perpendicular to the angle. In consideration of the swelling of the skin when the stable portion 17 is pressed against the skin, the axial distance between the end surface 17a of the stable portion 17 and the needle protruding surface 16a is preferably set to 1.3 mm or less.

Further, the inner diameter d of the stable portion 17 is set to a value equal to or larger than the diameter of the blister formed on the skin. Specifically, the distance T from the inner wall surface of the stabilizing portion 17 to the peripheral edge of the needle protruding surface 16a is set to be in the range of 4 mm to 15 mm. Thereby, it can prevent that blister formation is inhibited by pressure being applied to a blister from the inner wall surface of stable part 17.

The distance T from the inner wall surface of the stabilizing portion 17 to the periphery of the needle protruding surface 16a is not particularly limited as long as it is 4 mm or more. However, when the distance T is increased, the outer diameter of the stable portion 17 increases, so that it becomes difficult to bring the entire end surface 17a of the stable portion 17 into contact with the skin when the needle tube 5 is punctured into a thin arm like a child. . For this reason, the distance T is preferably set to 15 mm as a maximum in consideration of the thinness of the child's arm.

If the distance S from the peripheral edge of the needle protruding surface 16a to the outer peripheral surface of the needle tube 5 is 0.3 mm or more, the adjusting unit 16 does not enter the skin. Therefore, considering the distance T (4 mm or more) from the inner wall surface of the stable portion 17 to the periphery of the needle protruding surface 16a and the diameter (about 0.3 mm) of the needle protruding surface 16a, the inner diameter d of the stable portion 17 is 9 mm or more. Can be set.

In addition, the shape of the stable part 17 is not limited to a cylindrical shape, and may be formed in a rectangular tube shape such as a quadrangular column or a hexagonal column having a cylindrical hole at the center.

The guide portion 18 is a portion on the tip side of the connecting piece 24 with respect to the stabilizing portion 17. The guide portion 18 has a contact surface 18a that comes into contact with the skin. The contact surface 18 a is a part of the flat surface 24 a of the connection piece 24, and is a flat surface that is substantially parallel to the end surface 17 a of the stabilizing portion 17. By pressing the stable portion 17 until the contact surface 18a of the guide portion 18 comes into contact with the skin, the force with which the stable portion 17 and the needle tube 5 press the skin can always be secured above a predetermined value. Thereby, the part (equivalent to the protrusion length L) which protrudes from the needle | hook protrusion surface 16a of the needle tube 5 is punctured in skin reliably.

The distance Y from the contact surface 18a of the guide portion 18 to the end surface 17a of the stable portion 17 (hereinafter referred to as “guide portion height”) Y punctures the needle tube 5 and the stable portion 17 by pressing the skin with an appropriate pressing force. Its length is set so that it can. As a result, the guide portion 18 guides the pressing force applied to the skin by the needle tube 5 and the stabilizing portion 17, and the needle tip 5A (blade surface 5a) of the needle tube 5 can be reliably positioned on the upper layer portion of the skin. Can give you a sense of security. An appropriate pressing force of the needle tube 5 and the stabilizing portion 17 is, for example, 3 to 20N.

When the range of the inner diameter d of the stable portion 17 is 11 to 14 mm, the guide portion height Y is the length from the distal end surface of the guide portion 18 to the outer peripheral surface of the stable portion 17 (hereinafter referred to as “guide portion length”). It is determined appropriately based on X. For example, when the inner diameter d of the stabilizing portion 17 is 12 mm and the guide portion length X is 3.0 mm, the guide portion height Y is set in the range of 2.3 to 6.6 mm.

Next, the second member 12 will be described. The second member 12 is formed in a substantially cylindrical shape. One end portion of the second member 12 in the axial direction is an insertion portion 31 into which the base portion 15 of the first member 11 is inserted, and the other end portion is in the insertion portion 32 into which the discharge portion 52 of the syringe 3 is inserted. It has become.
The cylindrical hole 31 a of the insertion portion 31 is set to a size corresponding to the base portion 15 of the first member 11.

The insertion part 31 is provided with a fixing piece 34 connected to the connection piece 24 of the first member 11. The fixing piece 34 is formed as a ring-shaped flange that protrudes radially outward continuously from the distal end of the insertion portion 31. A flat surface 24b of the connection piece 24 provided on the first member 11 is brought into contact with and fixed to the fixed piece 34. Examples of the fixing method of the fixing piece 34 and the connection piece 24 include an adhesive, ultrasonic welding, laser welding, and a fixing screw.

The cylinder hole 32a of the insertion portion 32 is set to a size corresponding to the discharge portion 52 of the syringe 3, and the diameter continuously decreases toward the insertion portion 31 side. A thread groove 35 for screwing the discharge part 52 of the syringe 3 is formed on the inner surface of the fitting part 32.

As shown in FIG. 1, a hub side display portion 36 is provided on the outer peripheral surface of the insertion portion 32 as a recognition portion for recognizing that the insertion of the discharge portion 52 is completed. When the discharge part 52 is inserted into the insertion part 32, the hub side display part 36 coincides with a syringe side display part 54 (described later) provided in the discharge part 52 in the circumferential direction of the second member 12. Thereby, it can be made to recognize that the insertion to the insertion part 32 of the discharge part 52 was completed. Therefore, in the present embodiment, at least the second member 12 of the needle hub 6 is formed of a transparent or translucent synthetic resin so that the syringe-side display portion 54 can be visually recognized through the fitting portion 32.

The recognition portion according to the present invention is formed by providing a convex portion at one base end portion of the screw portion 53 or the screw groove 35 and providing a concave portion engaging with the convex portion at the other base end portion. May be. In this case, it is possible to recognize that the insertion of the discharge portion 52 into the insertion portion 32 is completed by the engagement between the convex portion and the concave portion.

Between the insertion part 31 and the insertion part 32, the engaging part 37 with which the elastic member 7 engages is provided. The engaging portion 37 is formed as a step portion protruding radially inward from the inner surface of the second member 12, and has engaging

surfaces

37 a and 37 b that are substantially orthogonal to the axial direction of the second member 12. . A flange portion 42 described later of the elastic member 7 is engaged with the engagement surface 37a of the engagement portion 37, and a stopper projection 43 of the elastic member 7 is engaged with the engagement surface 37b.

Next, the elastic member 7 will be described.
The elastic member 7 is disposed in the second member 12 of the needle hub 6 and is interposed between the first member 11 and the syringe 3. Then, the gap formed between the outer peripheral surface of the needle tube 5 protruding from the first member 11 on the base end 5B side and the second member 12 is filled in a liquid-tight manner. The elastic member 7 includes a main body 41, a flange 42 provided at one end of the main body 41 in the axial direction, and a stopper protrusion 43 provided at the other end of the main body 41.

The main body 41 is formed in a substantially cylindrical shape and has end faces 41a and 41b perpendicular to the axial direction. The end surface 41b of the base member 15 of the first member 11 is in contact with the end surface 41a of the main body 41, and the tip of the discharge unit 52 provided in the syringe 3 is in contact with the end surface 41b. That is, the end surface 41b is a contact surface with which the tip of the discharge portion 52 contacts.

The main body portion 41 is provided with an insertion hole 45 through which the proximal end 5B side of the needle tube 5 protruding from the end surface 15b of the base portion 15 is inserted. The insertion hole 45 extends in the axial direction of the main body 41 and is opened in the end faces 41a and 41b. The inner surface of the main body 41 is formed by an end surface side separation portion 46, a contact surface side separation portion 47, and a close contact portion 48.

The end surface side separation portion 46 forms an opening of the insertion hole 45 in the end surface 41a. The end surface side separation portion 46 is separated from the outer peripheral surface of the needle tube 5 and is formed in a taper shape such that the diameter of the insertion hole 45 continuously increases toward the end surface 41a. Thereby, the base end 5B side of the needle tube 5 protruding from the end surface 15b of the base portion 15 can be easily inserted into the insertion hole 45. Note that the shape of the end face side separation portion 46 in the insertion hole 45 is not limited to a tapered shape as long as the needle tube 5 can be easily inserted into the insertion hole 45.

The contact surface side separation portion 47 forms an opening of the insertion hole 45 in the end surface (contact surface) 41b. The contact surface side separation portion 47 is separated from the outer peripheral surface of the needle tube 5, and is formed in a taper shape such that the diameter of the insertion hole 45 continuously increases toward the end surface 41b. By providing the contact surface side separation portion 47 on the elastic member 7, it is possible to prevent the end surface 41 b side of the main body portion 41 from being elastically deformed and covering the proximal end 5 B of the needle tube 5.

The contact portion 48 is formed between the end surface side separation portion 46 and the contact surface side separation portion 47. The close contact portion 48 is in liquid tight contact with the outer peripheral surface of the needle tube 5. Thereby, it can prevent that the chemical | medical agent in the syringe 3 osmose | permeates between the needle tube 5 and the elastic member 7, and leaks to the 1st member 11 side of the needle hub 6. FIG. In addition, the outer peripheral surface of the contact portion 48 is in liquid-tight contact with the inner surface of the second member.

The flange portion 42 is formed in a ring shape that protrudes radially outward from the outer peripheral surface of the main body portion 41. The outer diameter of the flange portion 42 is substantially equal to the outer diameter of the base portion 15 of the first member 11. One flat surface of the flange portion 42 abuts on an engagement surface 37 a of the engagement portion 37 provided on the second member 12, and the other flat surface abuts on the end surface 15 b of the base portion 15 of the first member 11. The elastic member 7 is attached to the needle hub 6 by sandwiching the flange portion 42 between the engaging portion 37 of the second member 12 and the base portion 15 of the first member 11.

The stopper protrusion 43 is formed in a ring shape that protrudes radially outward from the outer peripheral surface of the main body 41, similarly to the flange 42. The stopper protrusion 43 engages with the engagement surface 37 b of the engagement portion 37 provided on the second member 12. The elastic member 7 is locked to move in the axial direction by the flange portion 42 and the stopper projection 43 engaging the engaging portion 37 of the second member 11. Thereby, it can prevent that a chemical | medical agent permeates between the elastic member 7 and the 2nd member 12, and leaks to the 1st member 11 side, and can improve a pressure | voltage resistant performance.

Examples of the material of the elastic member 7 include various rubber materials such as natural rubber, silicone rubber, and isobutylene rubber, various thermoplastic elastomers such as polyurethane and styrene, or mixtures thereof.

[Syringe]
The syringe 3 includes a syringe body 51 and a discharge unit 52 that is continuous with the syringe body 51. The syringe body 51 is a circular cylinder. The discharge part 52 protrudes from one end of the syringe body 51 in the axial direction, and is formed of a circular cylinder having an outer diameter smaller than that of the syringe body 51. The discharge part 52 is formed in a taper shape whose diameter continuously decreases toward the tip. An end surface 52a that is a tip of the discharge portion 52 is a plane orthogonal to the axial direction, and abuts against an end surface (abutment surface) 41b of the elastic member 7.

The outer peripheral surface of the discharge part 52 is provided with a screw part 53 for screwing onto the second member 12 of the needle hub 6 and a syringe-side display part 54. The syringe-side display portion 54 is recognized via the second member 12 of the needle hub 6 when the discharge portion 52 is inserted into the insertion portion 32 provided on the needle hub 6. When the insertion of the discharge portion 52 into the insertion portion 32 of the needle hub 6 is completed, it coincides with the hub side display portion 36 of the needle hub 6 in the circumferential direction.

In the pharmaceutical injection device of the present invention, the hub side display unit 36 and the syringe side display unit 54 are made to coincide with each other in the axial direction of the second member 12 so that the insertion of the discharge unit 52 is recognized. May be. For example, the hub-side display unit 36 may be provided at the distal end of the insertion portion 32 and the syringe-side display unit 54 may be provided at the end of the syringe body 51 on the discharge unit 52 side. In that case, even if the second member 12 is not transparent or semi-transparent, it can be recognized that the hub side display unit 36 and the syringe side display unit 54 coincide in the axial direction of the second member 12.

In the syringe body 51, a gasket (not shown) is accommodated. The space in the syringe main body 51 is liquid-tightly partitioned by a gasket, and one space communicating with the discharge portion 52 forms a liquid chamber 56 together with the space in the discharge portion 52. A plunger (not shown) is arranged in the other space in the syringe body 51. The plunger is connected to the gasket and protrudes from the opening at the other end of the syringe body 51. By operating this plunger, the gasket is moved in the axial direction within the syringe main body 51, and the medicine is sucked into the liquid chamber 56 and the medicine filled in the liquid chamber 56 is discharged.

As the material of the syringe body 51 and the discharge part 52, synthetic resin such as polycarbonate, polypropylene, polyethylene, etc. can be used, and glass or the like may be used.

[Assembly method of injection needle assembly]
Next, an assembly method of the injection needle assembly 2 will be described with reference to FIG.
FIG. 5A is a side view of a state in which the needle tube 5 is held by the first member 11. FIG. 5B is an explanatory view showing a state in which the second member 12 is connected to the first member 11 holding the needle tube 5.

To assemble the injection needle assembly 2, first, the needle tube 5 is attached to the first member 11. The length (protrusion length L) on the needle tip 5A side of the needle tube 5 projecting from the needle projecting surface 16a of the first member is set in the range of 0.9 to 1.4 mm. Therefore, when the needle tube 5 is attached to the first member 11, if the needle tip 5A side of the needle tube 5 is held, it is difficult to hold the needle tube 5 stably. As a result, the attaching operation of the needle tube 5 becomes complicated.

On the other hand, since the proximal end 5B side of the needle tube 5 is then surrounded by the second member 12, it can be set to an arbitrary length longer than the protruding length L. In the present embodiment, the length M on the proximal end 5B side of the needle tube 5 protruding from the end surface 15b is longer than the protruding length L. Therefore, when attaching the needle tube 5 to the first member 11, the proximal end 5 B side of the needle tube 5 protruding from the end surface 15 b of the base portion 15 in the first member 11 is held. Thereby, the needle tube 5 can be stably held, and the attaching operation of the needle tube 5 to the first member 11 can be easily performed.

To attach the needle tube 5 to the first member 11, the needle tube 5 is passed through the through hole 21 (see FIG. 3) of the first member 11 and the protruding length L is adjusted. Thereafter, the adhesive 20 (see FIG. 3) is injected from the injection hole 22 into the through hole 21, and the needle tube 5 is fixed to the base portion 15 of the first member 11. Thereby, the attaching operation of the needle tube 5 is completed, and the first member 11 holds the needle tube 5.

The needle tube 5 can be attached to the first member 11 by insert molding. In that case, the needle tip 5A side and the base end 5B side of the needle tube 5 are held by a mold. Thereby, the attitude | position of the needle tube 5 can be stabilized and a yield can be improved.

Next, the second member 12 engaged with the elastic member 7 is connected to the first member 11 holding the needle tube 5. That is, the base portion 15 of the first member 11 and the proximal end 5B side of the needle tube 5 are inserted into the insertion portion 31 of the second member 12, and the connection piece 24 of the first member 11 is fixed to the fixing piece 34 of the second member 12. Make contact. At this time, the proximal end 5B side of the needle tube 5 is inserted into the insertion hole 45 of the elastic member 7 disposed in the second member 12, and is in close contact with the contact portion 48 (see FIG. 3). Thereafter, the fixing piece 34 of the second member 12 is fixed to the connection piece 24 of the first member 11 by a fixing method such as adhesive, ultrasonic welding, laser welding, fixing screw, or the like.

Thereby, the injection needle assembly 2 is assembled. In a state where the assembly of the injection needle assembly 2 is completed, the proximal end 5B side of the needle tube 5 is disposed in the second member 12 while being inserted through the elastic member 7. Therefore, when the needle hub 6 is attached to the syringe 3 (see FIG. 2), it is possible to prevent a finger or the like from touching the proximal end 5B side of the needle tube 5.

When manufacturing an injection needle assembly in which the proximal end side of the needle tube does not protrude from the needle hub, the distal end side of the needle tube is generally held. However, when the length of the tip of the needle tube protruding from the needle hub is shortened to about 0.5 to 3.0 mm, the needle tube cannot be stably held, and the operation is very complicated and inefficient. turn into.

In the injection needle assembly 2 and the drug injection device 1 of the present embodiment, the second member 12 is connected to the first member 11 that holds the needle tube 5. The first member 11 holds the needle tube 5 so that both ends (the needle tip 5A side and the base end 5B side) of the needle tube protrude. Accordingly, even if the length of the needle tip 5A side of the needle tube 5 protruding from the needle hub 6 is shortened, the posture of the needle tube 5 can be stabilized by holding the proximal end 5B side of the needle tube 5, and the needle tube 5 The operation of attaching to the needle hub 6 can be easily performed.
[Assembly method of drug injection device]
Next, a method for assembling the medicine injection device 1 will be described.
As shown in FIGS. 1 and 3, the drug injection device 1 is assembled by attaching a syringe needle assembly 2 to a syringe 3. In order to attach the injection needle assembly 2 to the syringe 3, first, the discharge portion 52 of the syringe 3 is inserted into the insertion portion 32 of the injection needle assembly 2. Then, the screw portion 53 provided in the discharge portion 52 is screwed into the screw groove 35 of the insertion portion 32, and the syringe side display portion 54 of the discharge portion 52 coincides with the hub side display portion 36 of the injection needle assembly 2 in the circumferential direction. Let Thereby, mounting | wearing of the injection needle assembly 2 with respect to the syringe 3 is completed.

In a state where the assembly of the medicine injection device 1 is completed, the end surface 52a which is the tip of the discharge portion 52 is in contact with the end surface (contact surface) 41b of the elastic member 7 provided in the injection needle assembly 2 perpendicularly. 41b is pressed. Thereby, the end surface 52a of the discharge part 52 and the end surface 41b of the elastic member 7 are in liquid-tight contact, and the needle hole of the needle tube 5 and the liquid chamber 56 of the syringe 3 are communicated. As a result, a space can be prevented from being formed between the distal end of the discharge portion 52 and the proximal end 5B of the needle tube 5, and the remaining amount of the medicine can be reduced. In addition, the medicine filled in the liquid chamber 56 of the syringe 3 can be prevented from leaking into the needle hub 6 of the injection needle assembly 2, and a predetermined amount of medicine is discharged from the needle tip 5 A of the needle tube 5. Can do.

Further, the position of the needle tube 5 with respect to the needle hub 6 of the injection needle assembly 2 is precisely adjusted so that the end surface 52a of the discharge portion 52 is brought into perpendicular contact with the end surface 41b of the elastic member 7 so as to be in close contact with each other. There is no need. Therefore, the assembly work of the needle hub 6 and the needle tube 5 can be simplified, and the production efficiency can be improved.

Further, since the gap between the proximal end 5B side of the needle tube 5 and the needle hub 6 is sealed by the elastic member 7, when the drug is aspirated (primed) from a vial or the like, the outer peripheral surface of the needle tube 5 on the proximal end 5B side and the needle It is possible to prevent a space portion from being formed between the hub 6 and the hub 6. In the case where a space is formed between the outer peripheral surface of the proximal end 5B side of the needle tube 5 and the needle hub 6, the drug is discharged when the drug filled in the liquid chamber 56 is discharged from the needle tip 5A of the needle tube 5. The air in the space is compressed by the pressure for discharging, and the pressure is buffered, so that the medicine is accumulated in the space. Therefore, by preventing the space portion from being formed between the outer peripheral surface of the needle tube 5 on the proximal end 5B side and the needle hub 6, the dose of the medicine can be stabilized.

Further, according to the injection needle assembly 2 and the drug injection device 1 of the present embodiment, the contact surface side separation portion 47 is provided on the elastic member 7. Therefore, there is no possibility that the elastic member 7 is elastically deformed so that the end surface 41b of the elastic member 7 pressed against the end surface 52a of the discharge portion 52 enters the discharge portion 52, and the elastic member 7 forms a needle hole on the proximal end 5B side in the needle tube 5. Blocking can be prevented.

[How to use drug injection device]
Next, a method for using the drug injection device 1 will be described.
In order to puncture the living body with the needle tip 5A of the needle tube 5, first, the end surface 17a of the stabilizing portion 17 is opposed to the skin. Thereby, the needle tip 5A of the needle tube 5 is opposed to the skin to be punctured. Next, the drug injection device 1 is moved substantially perpendicularly to the skin, and the needle tip 5A is punctured into the skin and the end surface 17a of the stabilizing portion 17 is pressed against the skin. At this time, the needle protruding surface 16a can come into contact with the skin to deform the skin flatly, and the needle tip 5A side of the needle tube 5 can be punctured into the skin by the protruding length L.

Next, the end surface 17a of the stabilizing portion 17 is pressed until the contact surface 18a of the guide portion 18 contacts the skin. Here, the length of the guide portion height y (see FIG. 3) is set so that the needle tube 5 and the stabilizing portion 17 can puncture the skin with an appropriate pressing force. Therefore, the force that presses the skin by the stabilizing portion 17 becomes a predetermined value.

As a result, the user can recognize an appropriate pressing force of the stabilizing portion 17, and the needle tip 5A and the blade surface 5a of the needle tube 5 can be surely positioned on the upper skin portion. Thus, the guide part 18 becomes a mark for recognizing an appropriate pressing force of the stable part 17, so that the user can use the medicine injection device 1 with peace of mind.

Also, since the stabilizing portion 17 contacts the skin, the posture of the medicine injection device 1 is stabilized, and the needle tube 5 can be punctured straight to the skin. Moreover, the blurring which arises in the needle tube 5 after puncture can be prevented, and the administration of the medicine can be performed stably. For example, with a very short protruding tube of about 0.5 mm, the skin may not stick into the skin even if the needle tip is brought into contact with the skin. However, when the skin pressed against the stable portion 17 is pushed down in the vertical direction, the skin inside the stable portion 17 is pulled and tension is applied to the skin. Therefore, it is difficult for the skin to escape from the needle tip 5 A of the needle tube 5. Therefore, by providing the stabilizing portion 17, it is possible to obtain an effect that the needle tip 5A is more easily pierced into the skin.

After puncturing the skin with the needle tip 5A side of the needle tube 5, the plunger (not shown) is pushed to move the gasket (not shown) to the discharge part 52 side. As a result, the medicine filled in the liquid chamber 56 of the syringe 3 is pushed out from the discharge part 52, passes through the needle hole of the needle tube 5, and is injected into the upper skin part from the needle tip 5 A. At this time, since no space is formed between the distal end of the discharge portion 52 and the proximal end 5B of the needle tube 5, the remaining amount of the medicine can be reduced.

2. Second Embodiment [Drug Injection Device]
Next, a second embodiment of the drug injection device of the present invention will be described with reference to FIG.
FIG. 6 is a cross-sectional view of a second embodiment of the drug injection device.

As shown in FIG. 6, the medicine injection device 61 is composed of an injection needle assembly 62 and a syringe 3 to which the injection needle assembly 62 is detachably connected. The injection needle assembly 62 has the same configuration as the injection needle assembly 2 according to the first embodiment. The injection needle assembly 62 is different from the injection needle assembly 2 in that a stabilizing portion 67 and a guide portion 68 are provided on the second member 65 of the needle hub 63. Therefore, here, the stabilizing part 67 and the guide part 68 will be described, and the same reference numerals are given to the parts common to the injection needle assembly 2 and the redundant description will be omitted.

The needle hub 63 includes a first member 64 that holds the needle tube 5 and a second member 65 into which the discharge portion 52 of the syringe 3 is inserted. The first member 64 is different from the first member 11 according to the first embodiment in that the stabilizing portion 17 is not provided on the connection piece 24 of the base portion 15. Since the other structure of the 1st member 64 is the same as the 1st member 11, description is abbreviate | omitted.

The stabilizing part 67 and the guide part 68 are continuously provided at the tip of the fixed piece 34 provided on the second member 65. The stabilizing portion 67 protrudes in the axial direction of the second member 65 and is formed in a cylindrical shape that covers the periphery of the adjusting portion 16 through which the needle tube 5 passes, and is provided to be spaced apart from the needle tip 5A of the needle tube 5 in the radial direction. ing. A cap 8 (see FIG. 1) is detachably fitted to the stabilizing portion 67.

The end surface 67a of the stabilizing portion 67 is located on the proximal end 5B side of the needle tube 5 with respect to the needle protruding surface 16a of the adjusting portion 16, but is on the same plane as the needle protruding surface 16a or the needle tube 5 with respect to the needle protruding surface 16a. It may be located on the needle tip 5A side. The inner diameter d of the stabilizing portion 67 and the distance T from the inner wall surface of the stabilizing portion 67 to the peripheral edge of the needle protruding surface 16a are set in the same manner as in the first embodiment.

The guide portion 68 protrudes in the circumferential direction of the second member 65 and has a contact surface 68a that comes into contact with the skin. The contact surface 68 a is a plane that is substantially parallel to the end surface 67 a of the stabilizing portion 67. The distance Y (hereinafter referred to as “guide portion height”) Y from the contact surface 68a of the guide portion 68 to the end surface 67a of the stable portion 67, and the length (from the tip surface of the guide portion 68 to the outer peripheral surface of the stable portion 67) Hereinafter, it is referred to as “guide portion length.”) X is set in the same manner as in the first embodiment.

In the injection needle assembly 62 and the drug injection device 61 configured as described above, it is not necessary to precisely adjust the position of the needle tube 5 with respect to the needle hub 63, and the remaining amount of drug can be reduced. Moreover, while the force which presses skin by the stable part 67 can be made into predetermined value, the guide part 68 becomes a mark which recognizes the appropriate pressing force of the stable part 67, and a user can use the medicine injection device 61 in comfort. Can be used.

3. Third Embodiment [Drug Injection Device]
Next, a third embodiment of the drug injection device of the present invention will be described with reference to FIGS.
FIG. 7 is a cross-sectional view of a third embodiment of the drug injection device. FIG. 8 is an exploded sectional view showing a third embodiment of the drug injection device.

7 and 8, the drug injection device 71 includes an injection needle assembly 72 and a syringe 3 to which the injection needle assembly 72 is detachably connected. The injection needle assembly 72 has the same configuration as that of the injection needle assembly 2 according to the first embodiment. The only difference between the needle assembly 72 and the needle assembly 2 is the elastic member 74. Therefore, here, the elastic member 74 will be described, and portions common to the injection needle assembly 2 will be denoted by the same reference numerals and redundant description will be omitted.

The injection needle assembly 72 of the medicine injection device 71 includes a hollow needle tube 5 having a needle hole, a needle hub 6 to which the needle tube 5 is fixed, an elastic member 74 disposed in the needle hub 6, and a needle hub 6. And a cap 8 (see FIG. 1) that is detachably attached.

The elastic member 74 is disposed in the second member 12 of the needle hub 6 and is interposed between the first member 11 and the syringe 3. The elastic member 74 includes a main body portion 41, a flange portion 42 provided at one end of the main body portion 41 in the axial direction, and a stopper protrusion 43 provided at the other end of the main body portion 41.

A needle side valve body 75 is provided in the contact surface side separation portion 47. The needle-side valve body 75 is formed as a cylindrical protrusion that covers the outer periphery of the needle tube 5. The outer peripheral surface of the needle side valve body 75 is formed in a taper shape such that the diameter continuously decreases toward the tip. When the chemical solution flows into the contact surface side separation portion 47, the needle side valve body portion 75 is pressed by the chemical solution and is deformed so as to be in close contact with the needle tube 5, thereby improving the pressure resistance performance.

The flange portion 42 is formed in a ring shape that protrudes radially outward from the outer peripheral surface of the main body portion 41. The outer diameter of the flange portion 42 is substantially equal to the outer diameter of the base portion 15 of the first member 11. One flat surface 42 a of the flange portion 42 is the same flat surface as the end surface 41 a of the main body portion 41. A ring protrusion 44 is provided on the flat surface 42a. The ring protrusion 44 abuts against the end surface 15 b of the base portion 15 of the first member 11 and is crushed. The other flat surface 42 b of the flange portion 42 abuts on an engagement surface 37 a of the engagement portion 37 provided on the second member 12. The elastic member 74 is attached to the needle hub 6 by sandwiching the flange portion 42 between the engaging portion 37 of the second member 12 and the base portion 15 of the first member 11.

The stopper protrusion 43 is formed in a ring shape that protrudes radially outward from the outer peripheral surface of the main body 41, similarly to the flange 42. The stopper protrusion 43 engages with the engagement surface 37 b of the engagement portion 37 provided on the second member 12. The elastic member 74 is locked to move in the axial direction by the flange portion 42 and the stopper projection 43 engaging the engaging portion 37 of the second member 12. Thereby, it can prevent that a chemical | medical solution permeates between the elastic member 74 and the 2nd member 12, and leaks to the 1st member 11 side, and can improve a pressure | voltage resistant performance.

Examples of the material of the elastic member 74 include various rubber materials such as natural rubber, silicone rubber and isobutylene rubber, various thermoplastic elastomers such as polyurethane and styrene, or mixtures thereof.

Also in the injection needle assembly 72 and the drug injection device 71 configured as described above, it is not necessary to precisely adjust the position of the needle tube 5 with respect to the needle hub 6, and the remaining amount of drug can be reduced. Moreover, while the force which presses skin by the stable part 17 can be made into a predetermined value, the guide part 18 becomes a mark which recognizes the appropriate pressing force of the stable part 17, and the user can use the medicine injection device 61 with peace of mind. Can be used.

Furthermore, according to the injection needle assembly 72 and the drug injection device 71, even if the drug discharged from the discharge part 52 of the syringe 3 leaks to the contact surface side separation part 47, the leaked drug is not lost in the needle. In order to press the side valve body portion 75, the needle side valve body portion 75 is pressed against the outer peripheral surface of the needle tube 5. Thereby, the pressure resistance performance between the needle tube 5 and the elastic member 74 can be improved. As a result, it becomes difficult for the medicine to leak to the first member 11 side of the needle hub 6, and the amount of the medicine to be administered to the upper skin portion can be stabilized.
4). Fourth Embodiment [Injection Needle Assembly]
Next, a fourth embodiment of the injection needle assembly and drug injection device of the present invention will be described with reference to FIG.
FIG. 9 is a cross-sectional view of an elastic member according to a fourth embodiment of the injection needle assembly and the medicine injection device.

The fourth embodiment of the injection needle assembly and drug injection device has the same configuration as the needle assembly 72 and drug injection device 71 of the third embodiment. The fourth embodiment of the injection needle assembly and drug injection device is different from the injection needle assembly 72 and drug injection device 71 only in the elastic member 81. Therefore, here, the elastic member 81 will be described.

As shown in FIG. 9, the elastic member 81 includes a second member side valve body portion 83 in addition to the needle side valve body portion 75 of the elastic member 74 according to the third embodiment. Since the configuration other than the second member side valve body portion 83 is the same as that of the elastic member 74, the same reference numerals are given to portions common to the elastic member 74, and redundant description is omitted.

The second member side valve element 83 is provided on the other flat surface 42 b of the flange 42. The second member-side valve element 83 protrudes from the outer edge portion of the flat surface 42b and is formed continuously in the circumferential direction. When the chemical liquid discharged from the discharge portion 52 of the syringe 3 enters between the elastic member 81 and the inner surface of the second member 12, the second member side valve body portion 83 is pressed by the chemical liquid, and the inner surface of the second member 12. And liquid tight. Thereby, the pressure resistance performance between the elastic member 81 and the inner surface of the second member 12 can be improved. The material of the elastic member 81 is the same as that of the elastic member 74 of the first embodiment.

According to the fourth embodiment of the injection needle assembly and the medicine injection device, the drug solution leaking to the contact surface side separation portion 47 presses the needle side valve body portion 75, thereby causing the needle side valve body portion 75 to be It is pressed against the outer peripheral surface of the needle tube 5 and deforms so as to be in close contact with the needle tube 5. Thereby, the pressure resistance performance between the needle tube 5 and the elastic member 81 can be improved. Further, the chemical liquid leaked between the main body portion 41 and the second member 12 presses the second member side valve body portion 83 against the inner surface of the second member 12. Thereby, the second member side valve body 83 is deformed so as to be in close contact with the inner surface of the second member 12, and the pressure resistance performance between the second member 12 and the elastic member 81 can be improved. As a result, the drug solution is less likely to leak to the first member 11 side of the needle hub 6, and the amount of the drug to be administered to the upper skin portion can be stabilized.

In the above-described fourth embodiment, the second member-side valve body portion 83 is provided on the flange portion 42 of the elastic member 81. However, the valve body pressed against the inner surface of the second member 12 according to the present invention may be provided so as to protrude from the outer peripheral surface of the main body 41 of the elastic member 81.

5. Experimental Example of Pressure Resistance Next, an experimental example in which the pressure resistance performance by the elastic member of the injection needle assembly and the drug injection device of the present invention has been confirmed will be described.
The experiment is related to the elastic member 74 (see FIG. 8) according to the third embodiment, the elastic member 81 (see FIG. 9) according to the fourth embodiment, and the first and second embodiments. It performed about the elastic member 7 (refer FIG. 4).

In the experiment, a 33 gauge straight needle was used as the needle tube 5, and the needle tube 5 was fixed to the first member 11 of the needle hub 6 with a photocurable adhesive. Further, an elastic member is interposed between the first member 11 and the second member 12, and the first member 11 and the second member 12 are joined by ultrasonic fusion in a state in which the needle tube 5 penetrates the elastic member, and is elastic. The needle assembly was assembled according to the type of member. Subsequently, a syringe 3 was attached to each injection needle assembly, and a drug injection device was assembled for each type of elastic member.

Next, the liquid chamber 56 of the syringe 3 was filled with liquid, and the tip of the needle tube 3 was sealed. Subsequently, the failure of each elastic member was detected by pushing the plunger at 50 mm / min (min) with a static test device (autograph). The failure of each elastic member was detected from a strength-stroke curve obtained by a static test apparatus, and the breaking strength of each elastic member was measured from the detection result. Next, the pressure (pressure resistance performance) applied to each elastic member was calculated from the breaking strength and the cross-sectional area in the direction orthogonal to the axial direction of the discharge portion 52 of the syringe 3.

The experiment was performed 10 times for each type of elastic member in consideration of assembly errors and dimensional errors of the drug injection device. Then, the minimum value, maximum value, and average value of the pressure applied to the elastic member were calculated. The experimental results are shown in Table 1.

As shown in Table 1, when the elastic member 74 provided with the needle side valve body portion 75 is used, a pressure resistance performance of about 3.0 to 5.0 MPa is obtained, and the needle side valve body portion 75 and the second member side valve are provided. When the elastic member 81 provided with the body portion 83 was used, a pressure resistance performance of about 3.5 to 5.0 MPa was obtained. On the other hand, when the elastic member 7 not provided with the

valve bodies

63 and 83 is used, a pressure resistance performance of about 0.7 to 1.0 MPa is obtained. Therefore, the elastic member 74 provided with the needle side valve body portion 75 and the elastic member 81 provided with the needle side valve body portion 75 and the second member side valve body portion 83 are more than the elastic member 7 provided with no valve body. It was confirmed that the breakdown voltage was increased (the breakdown voltage performance was improved).

Although not shown in Table 1, it was confirmed that the elastic member 74 provided with the needle-side valve body 75 has a higher pressure resistance than the elastic member provided only with the second member-side valve body 83. . Accordingly, it was found that the pressure resistance performance is improved by providing the valve body pressed against the outer peripheral surface of the needle tube 5 rather than providing the valve body pressed against the inner surface of the second member 12.

The embodiments of the drug injection device and the needle assembly of the present invention have been described above, including their effects. However, the needle assembly and the drug injection device of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention described in the claims. is there.

In the above-described first to fourth embodiments, the end surface 52a of the discharge portion 52 in the syringe 3 is brought into perpendicular contact with the end surface 41b of the elastic member 7 (74, 81) so that they are in liquid-tight contact with each other. .
However, the liquid chamber 56 of the syringe 3 and the needle tube 5 can be communicated with each other even if the end surface 52a of the discharge portion 52 does not contact the end surface 41b of the elastic member 7 (74, 81). Therefore, the end surface of the discharge portion according to the present invention does not necessarily abut on the end surface of the elastic member. For example, when the dimensional variation of the syringe 3, the second member 12, or the elastic member 7 or the variation of the user's assembly method occurs, the end surface 52 a of the discharge portion 52 may not contact the end surface 41 b of the elastic member 7. .
The present invention allows these variations, does not require positioning with high accuracy, and sufficiently achieves the intended effect.
In order to reduce the dead volume, it is preferable to shorten or eliminate the distance between the end surface 52a and the end surface 41b.

In the above-described first to fourth embodiments, the proximal end 5B of the needle tube 5 is inserted into the discharge part 52 of the syringe 3. However, as the medicine injection device according to the present invention, the proximal end 5B of the needle tube 5 may not be inserted into the discharge part 52 of the syringe 3. For example, the base end 5 B of the needle tube 5 may be positioned on substantially the same plane as the end surface 52 a of the discharge part 52.

In the above-described first to fourth embodiments, the discharge part 52 of the syringe 3 is screwed into the fitting part 32 of the needle hub 6 (63). However, as the medicine injection device according to the present invention, the discharge part 52 may be connected to the insertion part 32 only by fitting. In that case, as in the first to fourth embodiments, it is preferable to form the discharge portion 52 in a tapered shape such that the diameter continuously decreases toward the tip. As a result, even if manufacturing variations occur in the dimensions of the discharge portion 52 and the insertion portion 32, the end surface 52a of the discharge portion 52 and the end surface 41b of the elastic member 7 (74, 81) can be liquid-tightly adhered. .

In the first to fourth embodiments described above, the needle hub 6 (63) is provided with the stabilizing portion 17 (67) and the guide portion 18 (68). However, the drug injection device and the injection needle assembly according to the present invention can be configured such that the syringe is provided with a stabilizing portion and a guide portion.

1, 61, 71 ... Drug injection device, 2, 62, 72 ... Injection needle assembly, 3 ... Syringe, 5 ... Needle tube, 5A ... Needle tip, 5B ... Base end, 5a ... Blade surface, 6, 63 ...

Needle hub

7, 74, 81 ... elastic member, 8 ... cap, 11, 64 ... first member, 12, 65 ... second member, 15 ... base portion, 16 ... adjusting portion, 16a ... needle protruding surface, 17, 67 ... Stable part, 18, 68 ... guide part, 20 ... adhesive, 21 ... through hole, 24 ... connection piece, 31 ... insertion part, 32 ... insertion part, 34 ... fixed piece, 35 ... screw groove, 36 ... hub side display Part (recognition part), 37 ... engaging part, 41 ... main body part, 41a ... end face, 41b ... end face (contacting surface), 42 ... flange part, 43 ... stopper projection, 45 ... insertion hole, 46 ... end face side Separation part, 47 ... contact surface side separation part 48 ... Close contact part 51 ... Syringe body 52 ... Discharge part 52a ... End face (tip) 53 ... Screw part 54 ... Syringe side display part 56 ... Liquid chamber 75 ... Needle side valve body part 83 ... No. 2-member side valve element

Claims

A needle tube having a needle tip pierced into the skin;
A needle hub having a first member for holding the needle tube and a second member into which a discharge portion of the syringe is inserted;
An elastic member disposed inside the second member, in close contact with the inner surface of the second member, and having an insertion hole through which the needle tube is inserted;
An injection needle assembly comprising:
2. The injection needle assembly according to claim 1, wherein the elastic member has a contact surface that comes into contact with a distal end of a discharge portion of the syringe.
3. The injection needle assembly according to claim 2, wherein the elastic member has an abutment surface side separation portion that forms an opening of the insertion hole in the abutment surface and is separated from the peripheral surface of the needle tube. .
The said elastic member has an end surface opposite to the said contact surface, and an end surface side separation part which forms the opening of the said insertion hole in the said end surface, and is spaced apart from the outer peripheral surface of the said needle tube. 4. The needle assembly according to 3.
The injection needle assembly according to any one of claims 1 to 4, wherein the elastic member has a flange portion sandwiched between the first member and the second member.
6. The needle-side valve body portion that is pressed against the outer peripheral surface of the needle tube by being pressed by the liquid medicine discharged from the discharge portion of the syringe is provided on the elastic member. A syringe needle assembly according to claim 1.
The second elastic member is provided with a second member-side valve body portion that is pressed against the inner surface of the second member by being pressed by the chemical liquid discharged from the discharge portion of the syringe. A needle assembly as described.
The first member holds the needle tube so that both ends of the needle tube protrude,
The second member is connected to the first member in a state of holding the needle tube, and surrounds a proximal end side opposite to the needle tip side of the needle tube protruding from the first member. Item 8. The needle assembly according to any one of Items 1 to 7.
9. The needle set according to claim 8, wherein the length of the needle tube protruding from the first member is shorter than the length of the proximal end of the needle tube protruding from the first member. Solid.
The injection needle assembly according to any one of claims 1 to 9, wherein a thread groove for screwing the syringe is formed in the second member.
The needle assembly according to any one of claims 1 to 10, wherein the second member is provided with a recognition unit for recognizing that the insertion of the syringe is completed.
12. An adjustment unit provided around the needle tip side of the needle tube and having a needle projecting surface that contacts the skin when the needle tip of the needle tube is punctured into a living body. The syringe needle assembly according to any one of the above.
The injection needle assembly according to claim 12, wherein the adjustment portion is formed integrally with the first member.
The needle hub is formed with a stabilizing portion that is arranged in a radial direction away from the needle tip of the needle tube and that contacts the skin when the needle tip of the needle tube is punctured into a living body. The needle assembly according to claim 12 or 13.
The injection needle assembly according to claim 14, wherein the stabilizing portion is formed integrally with the first member.
The injection needle assembly according to any one of claims 1 to 15, wherein the needle tube is 26 to 33 gauge.
A syringe having a discharge part;
A needle tube having a needle tip pierced into the skin;
A needle hub having a first member holding the needle tube, and a second member into which a discharge portion of the syringe is inserted;
An elastic member disposed inside the second member, in close contact with the inner surface of the second member, and having an insertion hole through which the needle tube is inserted;
A drug injection device comprising: